As they stood outside the commandeered government building in the town of Mohassen, it was hard to distinguish Abu Khuder’s men from any other brigade in the Syrian civil war, in their combat fatigues, T-shirts and beards.

But these were not average members of the Free Syrian Army. Abu Khuder and his men fight for al-Qaida. They call themselves the ghuraba’a, or “strangers”, after a famous jihadi poem celebrating Osama bin Laden’s time with his followers in the Afghan mountains, and they are one of a number of jihadi organisations establishing a foothold in the east of the country now that the conflict in Syria has stretched well into its second bloody year.

They try to hide their presence. “Some people are worried about carrying the [black] flags,” said Abu Khuder. “They fear America will come and fight us. So we fight in secret. Why give Bashar and the west a pretext?” But their existence is common knowledge in Mohassen. Even passers-by joke with the men about car bombs and IEDs.